Apparatus for the directional transmission or reception of wave energy



GE. 23, 1934. w, RUDOLPH 1,977,974 APPARATUS FOR THE DIRECTIONAL TRANSMISSION OR RECEPTION OF WAVE ENERGY Filed June 13. 1951 Patented Uct. 1934 UNITED STATES PATENT OFFICE APPARATUS FOR THE DIRECTIONAL TRANSMISSION OR RECEPTION OF WAVE ENERGY Wilhelm Rudolph, Kiel, Germany, assignor to Electroacustic Gesellschaft mit beschr Haftung, Kiel, Germany, a firm Application June 13, 1931, Serial No. 544,267 In Germany April 4, 1930 4Claims.

mission or reception, to the same generator or,

indicator (telephone) through a variable compensating means, whereby the direction of transmission or reception may be adjusted. The determinations of directions are made by-the interference method, the compensator being adjusted until the impulses of all receivers arrive at the indicator, common to all receivers, at one and the same time at which time a maximum intensity of sound is heard in the telephone, the bearings of the sound source thus being derived from-the adjustment of the compensator. Instead of a maximum intensity also an adjustment to minimum intensity in the indicator may be used for finding the direction of the incoming sound. For directional transmission of wave energy the adjustable time lag circuits of the so-called compensator between the wave generator and the difierent oscillators of the group have to be adjusted so that the oscillations of the different oscillators have a proper phase relation according to the direction in. which the wave beam is to send. Compensators of this type are disclosed more. particularly in the U. S. Patents to Hecht and Stenzel No. 1,893,741 andto Hecht No. 1,969,005, in connection with an oscillator arrangement in a horizontal plane, such as would be used for a stationary submarine sound transmitter or receiver. In the embodiment of such a horizontal receiver arrangement on a vessel below its water line, difliculties are encountered, insofar as very few horizontally extending surfaces exist on that portion of the hull of sufficient extent to arrange an appreciable number of oscillators in an even approximately horizontal plane.

The object of the present invention is to provide an improved installation, and particularly an improved arrangement of the oscillators on a ship for submarine sound receiving or signalling. According to the present invention, the oscillators are arranged on the bow of a ship on both sides of the keel below the water line substantially in the form of semi-circles or semiellipses, the oscillators all being permanently connected, during transmission or reception, to the same generator or indicator through a compensator. This compensator is, however, designed in its contact arrangement not for the configuration of the oscillators as it appears on the vessels hull, but for a configuration resulting from the projection of the actual configuration upon a horizontal plane. This results in the same effeet as if the oscillators themselves were arranged in that configuration in a horizontal plane. I am thus enabled to utilize the subaqueous portion of the hull as a carrier for the oscillator, irrespective of its irregular shape, without interferring with a comparatively simple compensator design which renders possible sharply defined directional reception and transmission. Preferably the distance between adjacent oscillators is chosen as small as possible, in any case not greater than about 60 centimeters for the transmission or reception of the customary sound frequencies.

In order that the invention may be more clearly ,understood it will now be described with reference to the accompanying drawing in which Fig. 1 shows the arrangement on the ship.

Fig. 2 shows the projection of the receivers onto a horizontal plane.

Fig. 3 shows the connection of the receivers with the compensator, and Fig. 3a shows a detail 30 of Fig. 3 to be explained later.

Fig. 1 shows the bow of the ship 20, CW is the water line. Below the latter, the receivers on the starboard side 1-6 are illustrated by full circles. They lie approximately, on a semi-ellipse 95 which is open towards the keel. The same group is to be imagined on the port side. Instead of this, the receivers can also be arranged in semicircles. In the same way the semi-ellipses or semi-circles can be open towards the top, as is indicated in Fig. 1 by dotted circles. The compensator is indicated at 30; 13 is its pointer, and 14 the scale from which the direction is read 011.

In-the projection onto the horizontal plane, the receivers on both sides of the ship form together a complete circle or a. complete ellipse, according to the way they are. arranged on the vessel. For instance, the receiver projections'1-12 in Fig. 2 f form a complete ellipse, in accordance with the elliptical arrangementin'Fig. 1. The total re- 0 tardation value of the compensator line orlines and the retardation value of the individual sections of it or of them has to be calculated according to the greatest diameter of projection of the I group of oscillators upon the plane 'of propagation of sound (in water generally a horizontalplane) and according to the form of the said projection. The mode of action of such a group is j as follows:If sound arrives from port or starboard, it is received mainly by the half-group 1 situated on the port or starboard side respectively of the ship. Its circular or elliptical shape, together with a close arrangement of the receivers next to one another, ensures a direction determination which is perfectly clear and practically free from secondary maxima. If the sound arrives from the front, the whole group determines the direction, that is, both half-groups operate together, so that also in this direction the maximum of directional sharpness can be obtained, because the width of the hull of the ship below the water line is utilized to the best possible degree. The directional sharpness corresponds, abeam the ship, to the large axis a in Fig. 2 and, toward the front, to the small axis 1) of the ellipse.

The circuit of the arrangement is shown in Figs. 3 and 3a where connection is made to a so-called strip compensator 30 as described in the application of one Alexander Fischer Serial No. 491,740, filed October 28, 1930. The compensator consists, similar to the construction shown in said application, of conductor strips 31, 32, etc. up to 42, 43, insulated from one another, each strip being connected to a section of the retardation line 29, to

one end of which line the telephone 25 is connected. Each of the receivers 1-12 is connected at one of its terminals directly to a common lineleading to the compensator, and at the other terminal to an individual contact brush, cooperating with a collector shaft 2'7 rotating with a circular disc 28 (here imagined to be transparent and indicated by a dashed circle), whereby connection is made with further insulated contacting members (indicated by crosses) which are carried by the disc and move over the surface of the compensator strips when the compensator knob is operated. Fig. 3a shows the slip rings and sliding brushes of the collector 27.

If the ship is a submarine boat, the arrangement of the receivers is preferably effected in front of the pressure tank, which is indicated by dashes in Fig. 1 at 50.

The number of receivers of a group is determined by the amount of space available below the water line, that is, in practice, by the size of the ship. The larger the number the larger can the group figure be madeand thus the greater will be the accuracy of direction determination. In arranging the receivers, the ships construction, especially the position of the ribs, must, of course, be taken into account. It is by no means necessary for all the receivers to be spaced the same distance apart. It is also not necessary for the circular or elliptical shape. to be accurate in a mathematical sense. On the contrary, it is only important, in general, that the arrangement of several receivers of a half-group in a straight line be avoided, because disturbing secondary maxima and ambiguities in the direction determination will thereby occur. The advantage of such an arrangement is that the irregular contour or curvature of the hull, does not interfere in the least with the arrangement of the oscillators. The designer of the oscillator system merely proceeds placing the oscillators on the hull in a configuration most convenient for the hull,

'using a semi-circular or semi-elliptical configuration if possible, which however owing to the shape of the hull would extendin several planes.

: geometrical projection into .a horizontal; plane.

' Hereagain theg'dcsigner takes-carefm the oseil lator. distribution onthe hull that thisprojection has the most convenient form, for instance $11-v cle or an ellipse. Then he proceeds to use that projection configuration for the design of his compensator as if this projection were the actual oscillator configuration, and as if that were 10- catedoriginally in the plane of the energy propagation. Thus, according to my novel idea it becomes possible to treat an oscillator arrange-. ment, which by force of circumstances must be arranged in an area which extends in several planes, as if it extended only in the plane of the wave energy propagation, and to use readily available simple types of compensators heretofore customary in the art for oscillators located in the wave propagation plane, instead of using the more complicated multi-plane compensators, which must be designed each specifically for the parchanical impulse translating means, a group of at least three wave energy oscillators, mounted ,on each side of the vessel in its hull and in a space configuration, which when projected into a horizontal plane represents together with the projection of the other group a two-dimensional geometrical figure, and an adjustable compensator connected between said impulse translating means and all of said oscillators, for compensating for the time lag, incidental to each oscillator with respect to the wave front, on the basis of said geometrical figure, to render the impulses of all oscillators coincident. in said translating means at only one definite compensator adjustment corresponding to the direction of the arwave energy.

2. Arrangement on a vessel for horizontal di rectional transmission or reception of wave energy, comprising in combination one electro-mechanical impulse translating means, a group of at least three wave energy oscillators, mounted on each side of the vessel in its hull and in a space configuration, which when projected into a horizontal plane represents an ellipse, and an adjustable compensator connected between said impulse translating means and all of said oscillators, for compensating for the time lag, incidental to each oscillator with respect to the wave front, on the basis of said geometrical figure, to render the impulses of all oscillators coincident 'in said translating means at only one definite compensator adjustment corresponding to the direction of arriving wave energy.-

3. Arrangement on a vessel for horizontal directional transmission or reception of wave energy, comprising in combination one eleetro-mechanical impulse translatingmeans, a group of at least three wave energy oscillators, mounted vlag, incidental to each oscillator with respect to the wave front, on the basis of said geometrical figure, to render the impulses of all oscillators coincident in said translating means at only one definite compensator adjustment corresponding to the direction of the arriving wave energy.

4. Method of obtaining directional transmis-v sion or reception, with the aid of the interference method, of wave energy in a single plane of propagation by means of a plurality of wave energy oscillators arranged in a geometrical configura- WILHELM RUI DOLPH.

crmmcm: or CORRECJION.

Patent No. L977, 974.

October 23. "1934.

, WILHELM RUDOLPH.

lttis hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1,

filing date in Germany, -for heading to the printed specification,

line 9, in the read June 23,1930; and that the said Letters-Patent-should be read with this correction therein that the same may conform to the record of the case in the Patent (Mice.

Signed and sealed this 13th day of November, A.'D. 1934.

Les! ie Frazer:

"April 4, 1930" Acting Commissioner of Patents. 

